The present invention relates to decorative emblems which have a cured plastic layer over a decorative surface and a method for making such emblems. More particularly, it relates to decorative emblems produced by the method of coating a fluent plastic material onto a flat decorative foil shape to produce a thin positive meniscus which, when the plastic is cured, gives a lens effect to the decorative surface beneath.
Decorative plaques and emblems are widely used throughout a number of industries including the automotive and appliance industries. In the past, such plaques and emblems were formed by flowing a colored vitreous frit into a bronz substrate and firing it at 1250.degree. F. The glass-like vitreous enamel served to beautify the product and protect the decorative emblem from weathering. Today, plastics are primarily used for making such plaques and emblems. For example, the assignee of the present invention has been producing emblems since 1966 which have a molded or cast body into which plastic is deposited. A description of such products can be found in the July-August, 1972 issue of duPont Magazine, pp. 29-31.
Likewise, Loew, U.S. Pat. No. 3,654,062, discloses a process for injection molding a decorative Mylar facing sheet over a vinyl plastic body. The plaque is coated with a layer of protective varnish on the outer surface of the facing sheet. Gits, U.S. Pat. No. 3,246,066, is similar in that male and female molds are used to form a cavity into which a decorative foil is placed and into which a clear plastic material is injected. Prior to injecting a clear plastic material against the front face of the foil, the foil is precoated. Other molding processes such as compression molding are also known in the art. See for example, U.S. Pat. Nos. 2,244,565; 2,931,119; 3,075,249; and 3,114,597.
In Waugh, U.S. Pat. No. 4,100,010, assigned to the assignee of the present invention, there is disclosed an improved process of producing decorative emblems. That process involves casting a plastic material from a single nozzle onto decorative foil shapes to form a meniscus which when cured gives a lens effect to the top surface of the foil shape. A problem with that process is that the height of the lens cap so produced is considerable compared to the thickness of the foil substrate, requiring fairly large amounts of expensive plastic material. Another problem is that the foil shapes are cast individually by skilled workers, and the manufacturing process can as a result be too cumbersome and costly for some purposes and does not always yield the most efficient process for mass production. The same problems exist with respect to the methods of Beinbreck, U.S. Pat. No. 4,087,570 and Reed, U.S. Pat. No. 4,139,654, also assigned to the assignee of the present invention.
U.S. Pat. No. 4,292,827 discloses a process in which emblems are coated in sheets with a plastic material from a plurality of application tubes. However, this process has the disadvantage that the entire surface of the sheet is coated with plastic. This not only leads to a waste of material but requires tht the emblems be cut from the sheet with means capable of not only cutting the foil substrate but also of cutting through the hardened plastic. In accordance with the process taught in the application, cutting is performed in such a manner that a concavity is imparted to the surface. Control of this concavity formation adds additional complicating features.
Accordingly, the need exists for a method for coating clear plastic materials onto a decorative substrate less expensively, more efficiently, to produce an emblem having a relative thin lens cap.